Along with the divide between rich and poor in Europe, another has opened between the mobile and the stationary.

The subtitle of Benjamin Disraeli's novel Sybil, about Britain of the mid-19th century, refers to the "two nations" of rich and the poor. The gap between these two halves of society was a central preoccupation of social reformers during the Industrial Revolution. Nor has this divide between rich and poor in Europe gone away, despite the efforts of the welfare state. Indeed, in recent years, the divide has only grown wider.

I recently traveled by train from London to Berlin and was struck by a different divide that has opened up in Europe. These "two nations" are the mobile and the stationary. And this divide, like the one that so engaged Disraeli, has had an equally profound impact on the politics of the moment.

Europe has fully entered the era of the mobile. You can commute by train from London to Brussels in two hours, faster than the trip by Amtrak from New York to Washington, DC. For all British Prime Minister David Cameron's talk of the UK choosing the a la carte option for EU membership, his country is now tethered firmly by its Chunnel umbilicus. Once on the continent, the train system puts Amtrak to shame at every level: speed, reliability, comfort, food (well, the currywurst I ate on the train to Berlin was approximately equal to an Amtrak hotdog). For those in a greater hurry, cheap airline tickets bring people rapidly from Dublin to Athens and Lisbon to Gdansk.

The tribe of the mobile is not restricted to the leisure class. The opening of the borders within the European Union facilitated an extraordinary labor migration as Poles moved westward, the British moved south, Spaniards moved north, and the adventurous sought jobs eastward in Prague and Bucharest and Sofia. The definition of guest workers (gastarbeiter), as well as their overall numbers, has expanded enormously, and bureaucrats now prefer the term "mobile workers." Nor is it just the young who are on the move. "Retirement migration" has created the European version of snowbirds. And, of course, there are the involuntary migrants, escaping the war in former Yugoslavia or trafficked against their will to brothels.

This mobility within Europe, on top of the waves of immigrants and asylum-seekers coming from outside the continent, has destroyed any vestige of the ethnically homogenous European state. The end of empire, and the flow of people from former colonies to the imperial metropoles, had already made England and the Netherlands and France into multiethnic environments. But now even Scandinavia and Ireland are being remade by the new otherlanders. Europe has now become not just a continent of regions but a continent of neighborhoods: the French quarter of South Kensington in London, the Turkish environment of Kreuzberg in Berlin, the Vietnamese community in Warsaw's Praga section.

This is the Europe of shifting cosmopolitan identities: the Manhattanization of the continent. Philip Roth's brilliant novel The Counterlife imagines a movement called Diasporism devoted to the return of Jews not to Israel but to the Europe of Polish shtetls and tony German neighborhoods. This obviously hasn't happened. Instead, regardless of its religion, this half of Europe has embraced Diasporism, and the era of fixed national identities is over.

Or perhaps not. There is another Europe. After all, not everyone is on the move. The other half of Europe has stayed put. It has remained in the same place, the same village, even the same house for generations. It speaks of centuries of family involvement in municipal affairs or tending the same vineyards or defending the country against invaders. This part of Europe has no intention of pulling up roots and moving to some strange land. The younger generation might peel off and join mobile Europe. But still, someone continues to tend the family hearth.

According to a 2005 study, only 22 percent of Europeans moved outside their region or country – compared to 32 percent of Americans who moved outside the state where they were born. That's a very big majority of people who stay close to home.

The great debates raging in Europe today are a function of this divide between the mobile and the stationary. Do you support a headscarf ban, an end to the new construction of minarets, stricter controls on immigration, and a go-slow approach to European expansion? Or do you celebrate multicultural education, Gay Pride festivals, more generous benefits for foreign workers, and the greater diversity of restaurants in your neighborhood?

You could simply attribute this divide to liberals versus conservatives. But what makes these debates so heated is not so much the ideological division but the deep cultural division. Half of Europe clings to what it believes are native traditions tied to land, language, and traditional lifestyle. The other half has embraced a completely different Europe that is not defined by national identity or, at least, one national identity. There is hybrid Europe, and then there is the Europe that imagines itself to be a collection of indivisible nation-state billiard balls that can kiss or collide but not merge.

Let me be clear. Some of the people who are in flux are as traditional and conservative as you can get. And some of the people who are staying in one place are paragons of tolerance and open-mindedness. But the members of the first group, however conservative their mores might be, are creating a fundamentally new European reality that transcends their own personal politics.

We might celebrate the Europe of terroir, of culture based in a specific locale. But, increasingly, the people who will be perpetuating this terroir will themselves come from different lands – like Korean-Americans who become involved in Civil War reenactments or Italian-Americans who run gumbo restaurants in New Orleans. This comparison is not chosen at random. Europe is becoming ever more American in its demography. Once the exporter of immigrants, Europe must now refashion itself as an immigrant society.

The European Community was an effort to erase the traumas of the first and second World Wars. The new Europe Union, if it is to survive its current economic challenges, will similarly attempt to erase the traumas of the Cold War and the conflicts that immediately sprang up in its wake. But the EU must also grapple with a more fundamental tension between a traditional past and a multicultural future.

This tension between the mobile and the stationary can be creative and not just contentious. The two Europes could, for instance, consummate an opposites-attract marriage. But before we send out that particular marriage announcement, we'll have to see the political defeat of the Geert Wilders and Marie Le Pens and Victor Orbans of Europe and the victory of politicians and artists who are more sensitive to the paradoxes of modern European life.